1. Technical Field
The present invention relates to a system and method that controls access to peripheral devices. More particularly, the present invention relates to a system and method that shares a secret between the peripheral device and a computer system to protect usage of the peripheral device.
2. Description of the Related Art
Peripheral devices, such as removable nonvolatile storage devices, are increasingly popular, often because of their increased performance and decreased cost. These devices, such as Universal Serial Bus (USB) drives, are often used to provide external storage to a computer system used to backup data on the computer system. Other peripherals, such as printers, provide increased functionality to a computer system. Traditionally, these peripheral devices are connected to a user's computer system, such as a laptop computer system, and they often remain attached to the computer system even when the user is no longer using the computer system.
For example, a user might attach a USB drive in his or her computer system and schedule a backup of important documents or data that are copied from the computer system to the removable nonvolatile storage device on a periodic basis. Backup of documents and other data generally works better when the computer system is not being used by the user. First, if a document is currently being used by the user, it might not be able to be copied to the removable nonvolatile storage device. Second, a backup application often slows down a computer system making the system less responsive to the user. For these reasons, backup applications are often scheduled for time periods when the user is not using the system. If a user generally uses the system from 8:00 AM to 5:00 PM, a backup might be scheduled at an off-time, such as 3:00 AM, when the user is not likely to be using the system.
A challenge of using peripheral devices, such as removable nonvolatile storage devices and printers, is that they can be accessed by unauthorized users. For example, a challenge of using removable nonvolatile storage devices to backup documents and data is that the removable nonvolatile storage device is vulnerable to being removed from the system and the data stolen from the removable nonvolatile storage device. This is especially troublesome when the documents and data being backed up contain confidential or sensitive information. One approach to protecting the removable nonvolatile storage device is to lock the removable nonvolatile storage device in a secured housing, such as inside a locked desk, with the removable nonvolatile storage device being attached to the computer system using a longer cable. A challenge of this approach is that the secured housing might not always be available, such as when the user is traveling and attaches the removable nonvolatile storage device to his or her laptop computer system in a remote location, such as a hotel room. A second approach to protecting the removable nonvolatile storage device is to remove the removable nonvolatile storage device when the user is no longer using the computer system. A challenge of this approach is that the backup application would have to run when the user is at work using the system, potentially causing problems discussed above. Another challenge to this second approach is that the user might not remember to remove the removable nonvolatile storage device from the system at the end of the day. This is especially true when the connection is in an obscure location, such as in the back of a computer system where it might not be visible to the user.